Composition and method for weatherproofing fabrics



United States Patent No Drawing. Filed Sept. 1s, 1961, Ser. No. 138,5844 Claims. or. 260-334) This invention relates to the weatherproofing offabrics whereby the latter are made resistant to Wetting by water. I Ithas particular utility in operations wherein drycleaned garments madefrom a woven fabric are provided with a protective coating which affordsa high degree of water-repellency, While at the same time allowing airto pass freely through the fiber interstices.

Basically, the desired results are obtained by treating the fabric witha solution, in an organic solvent, of an alkyl titanate, a criticalamount of a glycol, and a vinyl ether polymer.

It is well known in the trade that water repellent garments which havebeen drycleaned one or more times will have lost substantially all oftheir original waterrepellency. While many compositions are availablefor restoring this quality, it is necessary to thoroughly remove orotherwise neutralize the residual detergent remaining in the drycleanedgarment before such water repellent compositions can be effectivelyapplied. These detergent-removal, pretreating steps are tedious andexpensive from a time consumption standpoint. In addition, unless thisremoval or neutralization step is performed with great care, poorwater-repellency is still obtained.

A further disadvantage of many water-repellent compositions now on themarket lies in their poor solubility in common drycleaning solvents.This necessitates that the treating bath be used at elevatedtemperatures to maintain the product in solution, thus introducing botha fume as well as a fire hazard.

In recent years, water repellents have been introduced which are lesssensitive to the effect of the residual drycleaning detergents. Many ofthese are based on com bin ations of aluminum or titanium esters andvarious hydrocarbon waxes, as exemplified, for instance in US.

Pats. Nos. 2,628,170 and 2,628,171. However, considerable detergentsensitivity still remains, so that it is necessary to rinse thedrycleaned garments in uncontaminated drycleaning solvent as a specialpretreatment prior to application of even these improved waterrepellents. In addition, they tend to produce a stiff, unwieldy fabric.Moreover, in order to develop their maximum eflectiveness, thesecompositions require that the treated garment be pressed at relativelyhigh temperatures, for example, on a commercial hot head press. Thisresults in a still stiffer hand and, in some cases, in actual damage tothe garments.

It is, therefore, an object of this invention to provide a novelWater-repellent composition adapted to be applied to textiles fromorganic solvent solution. A more particular object is to provide acomposition of this character which can be applied to the textile fabricwith good results in either the presence or absence of residual amountsof drycleaning detergent in the fabric material undergoing treatment,the resulting treated product being soft and having excellentwater-repellent qualities.

A further object is to provide a water-repellent composition whichdissolves readily at room temperatures to form a clear solution in thecommonly employed drycleaning solvents, and which retains its lifeindefinitely except for liquid carry-out, as previously drycleanedgarments containing residual detergent are treated in the solution.

Another object is to provide a composition of the afore said characterwhich develops its maximum effectiveness as the treated garments arepressed on a steam press, and which does not require exceptionally highheating during the pressing operation.

The nature of still other objects of the invention will be apparent froma consideration of the descriptive portion to follow.

We have discovered that the foregoing objects can be achieved by the useof a novel water-repellent composition comprising a long chain, vinylether polymer, a tetra-(lower) alkyl titanate and a critical amount,based on the titanate content, of a C -C glycol of the type having atleast one secondary hydroxyl group. The water-repellent composition isprepared by dissolving the above components, optionally along with othermaterials such as hydrocarbon oils and waxes, stearic or other longchain fatty acids, and resins such as polymerized beta-pinene, in anorganic solvent or solvent mixture. The conventional practice incarrying out the present invention is to formulate a concentratedsolution containing from about 30 to of the solvent, with the lattersolution then being diluted with a conventional drycleaning solvent toprepare the final solution with which garments are treated by thedrycleaner.

In carrying out the present invention good results have been obtainedwith compositions containing from about 1 to 4 parts of the titanateester, from about 2 to 5 parts of the vinyl ether polymer, and fromabout 0.1 to 0.5 mole of the glycol for each mole of titanate. The lowerlimit for the glycol varies with the particular titanate ester employed,the purpose of the glycol being to stabilize the ester againsthydrolysis. With tetra alkyl titanates wherein the alkyl groups eachcontain only 3 carbon atoms it may be necessary to use as much as 0.3mole of the glycol per mole of titanate to effect stabilization, thoughwith esters wherein the alkyl groups contain from 4 to 8 carbon atomsgood results are normally obtained with as little as 0.1 mole of theglycol. The factor of stabilization can be readily determined byobserving a freshly prepared solution of the composition in anappropriate organic solvent as the solution is allowed to stand for aperiod of 24 hours at room temperatures. Properly stabilized solutionsremain clear for this period, while those containing an insufiici'entportion of the glycol tend to become cloud-y. Simple experimentationthus determines the minimum amount of glycol to be employed, though inno case should the glycol content exceed about 0.5 mole per mole oftitanate ester since, as the glycol content exceeds this proportion, thewater-repellent qualities of the composition are rapidly lost asgarments containing residual detergents are treated there- As indicatedabove, the compositions hereof are formulated using about 1 to 4 partsof the tetra-(lower) alkyl titanate ester, these and other partsexpressed herein being on a weight basis. A- preferred range is fromabout 1.5 to 3 parts. The titanate ester is selected from the groupconsisting of those wherein each alkyl group contains from 3 to 8 carbonatoms, representative compounds being tetraisopropyl titanate,tetra-n-propyl titanate, tetran-butyl titanate, tetraisobutyl titanate,diisopropyl-di-nbutyl titanate, tetraamyl titanate, tetra-n-hexyltitanate, tetrakis (Z-ethylbutyl) titanate and tetrakis (2 ethylhexyl)titanate. Of these compounds, it is preferred to use tetraisopropyltitanate, a compound which normally requires from about 0.25 to 0.3 moleof glycol per mole of titanate for effective stabilization as the latteris dissolved in an organic solvent.

The composition contains from about 2 to 5 parts, and preferably 2.5 to4 parts, of a vinyl ether polymer. A preferred polymer is polymerizedvinyl octadecyl ether, though good results can be obtained with anypolymer having the general formula,

wherein n has a value of from about 12 to 22 and x has a value of atleast 5, the upper limit on the value of at being that imposed as asolvent-insoluble product is obtained. In the case of the vinyloctadecyl ether polymer noted above, n has a value of 18 and x has anaverage value of about 9.

The glycol employed in the composition is one containing from 6 to 9carbon atoms, and wherein, of the two hydroxyl groups, at least one issecondary in nature. Good results can be obtained, for example, with2-methyl- 2,4-pentanediol, 2,2-dimethyl-1,3-pentanediol and 2-ethyl-1,3-hexanediol. The preferred compound for use in the present inventionis 2-methyl-2,4-pentanediol, otherwise known commercially as hexyleneglycol.

To the titanate, glycol and ether polymer components of the compositionmay also be added various of the materials which are presently employedin water-repellent compositions. Thus, the mixture may include ahydrocarbon wax (parafiin or scale) in amounts up to about 50% of theweight of ether polymer employed. Mineral oil, which acts as an extenderand plasticizer can be used in amounts up to those substantiallyequaling the content of ether polymer, and the preferred compositions ofthis invention contain from 50 to 100% of mineral oil, based on polymerWeight. Similarly, the preferred compositions also include from about 10to 25%, in terms of the Weight of ether polymer, of a polymerizedbicyclic monoterpene hydrocarbon such as polymerized beta-pinene.

It is also possible to add a long chain fatty acid such as stearic acidin amounts up to about 50%, based on the weight of ether polymer. Stillother conventional ingredients can also be employed in the composition,if desired.

The composition is normally prepared by dissolving the variouscomponents mentioned above in a suitable organic solvent such as carbontetrachloride, perchlorethylene, trichlorethylene, Stoddard solvent andother petroleum hydrocarbon solvents commonly used in drycleaning. Aclear solution can be prepared in most instances using as little as 30%of solvent, though somewhat larger amounts (Le, 50%) are used in mostinstances.

Solutions of this character hold up well during storage, and while theytend to become turbid during cold weather,

vthey readily become clear on being warmed to room or i slightly highertemperatures.

The use of the polymerized beta-pinene component in the composition hasbeen found to facilitate clarification of such solutions at temperaturesof about 75 F., the pinene also acting to maintain the solution in aclear condition at somewhat lower temperatures than would otherwise bethe case.

In using the water-repellent solution in the treatment of either new ordrycleaned garments, the fabric is either dipped in or otherwiseimpregnated with a relatively dilute solution of the product. The extentof dilution will depend somewhat on liquid takeout, or amount ofsolution retained in the fabric after it has been allowed to hang or hasbeen subjected. to a centrifuging step preparatory to being heated atconventional drying temperatures (usually about 140 F.) to removecontained solvent. In general, good results are obtained with solutionscontaining a total of from about 5 to 20% by weight of the variousnon-solvent components. We find that from about 1.5 to 10 pounds ofsolid constituent in the solution will effectively treat 100 pounds ofgarments, though it is preferred to use from about 2.5 to 5 pounds ofsolids per 100 pounds of garments.

The examples given below illustrate the practice of the invention invarious of its embodiments. The Spray Ratings referred to therein wereobtained using Standard Test Method No. 22-1952 of the AmericanAssociation of Textile Chemists and Colorists (AATCC), the cotton poplinswatches or other fabric garments employed in the tests having beenfirst cleaned in a solvent containing from about 0.5 to 1% of an activedetergent. At the end of the cleaning cycle the excess detergentsolution was removed by centrifuge extraction and the fabric driedwithout rinsing or other treatment, the dried fabric so obtained beingfound to contain from about 0.1 to 0.25% by weight of the activedetergent.

In carrying out the operations of the examples, the drycleaned fabricswere dipped in a water-repellent solution prepared by firstincorporating about 50 parts by weight of the indicated nonsolventcomponents in 50 parts by weight of solvent (usually 35 parts carbontetrachloride and 15 parts Stoddard solvent) and then diluting this50-50 solution with 5 times its volume of solvent. The fabrics dipped inthis solution, after being centrifuged or otherwise freed of excessliquid, had a 35% retention of the treating liquid. The resultingfabrics after being dried a few minutes at room temperatures and thenfor about 30 minutes at 140 F., we found to contain about 3.5% by weightof the various non-volatile components of the particular treatingsolution employed. In cases where raincoats or other garments weredipped in the treating bath, each was accompanied by a swatch of cottonpoplin, and the switch was thereafter employed in making the SprayRating determination.

Briefly, the Spray Rating of the treated fabrics was measured by pouringa measured amount of water through a spray head and onto a stretchedpiece of fabric held at a 45 angle, at a set distance from the sprayhead. The amount of wetting is compared with a standard chart and ratedfrom 0 for complete wetting of the fabric to for no wetting.

Example 1 In this operation, the fabric was treated with awaterrepellent solution prepared as described above, using:

Parts Tetraisopropyl titanate 1 Hexylene glycol (0.474 mole/mole oftitanate) 0.2 2

, Polymcrized octadecyl vinyl ether The treated fabric had a SprayRating of 100.

Example 2 A mixture was prepared containing 24 lbs. of a polymerizedoctadecyl vinyl ether, 12 lbs. of white mineral oil, 12 lbs. oftetraisopropyl titanate, 1.8 lbs. hexylene glycol (0.355 mole/mole oftitanate), 30.1 lbs. Stoddard solvent and 20.1 lbs. carbontetrachloride. 1 gallon of this was diluted with 5 gallons of Stoddardsolvent. 5 garments and 5 cotton swatches, all of which had been cleanedwith a commercial drycleaning detergent and dried, were imersed in thesolution. The garments and swatches were then centrifuged to removeexcess solution and the excess solution combined with the originalsolution. The garments and swatches were dried at F. and pressed on acommercial steam press. Both the garments and switches had Spray Ratingsof 100. Seven more sets of garments and swatches were treated in turn inthe same manner. All garments and swatches had Spray Ratings of 100 andall had a soft, pleasant hand.

The foregoing operation was repeated, except that here one side of eachgarment was pressed on a commercial hot head press while the other wasnot pressed. Both sides had a Spray Rating of 100.

Example 3 Two solutions were prepared. One contained 24 lbs.

of a polymerized octadecyl vinyl ether, 12 lbs. of white mineral oil,1.8 lbs. of hexylene glycol (0.355 mole/mole of titanate), 12 lbs. oftetraisopropyl titanate, 35.5 lbs.

carbon tetrachloride and 14.7 lbs. of Stoddard solvent. The secondsolution contained 18 lbs. of a polymerized octadecyl vinyl ether, 3lbs. of a solution containing 65% polymerized B-p-inene in Stoddardsolvent, lbs. of white mineral oil, 2.2 lbs. hexylene glycol (0.434mole/mole of titanate), 12 lbs. tetraisopropyl titanate, 35.7 lbs.carbon tetrachloride and 14.1 lbs. Stoddard solvent.

On being cooled, the first solution became turbid at 16.5 C., while thesecond did not become turbid until 14.5 C. On rewarming, the secondsolution became clear at room temperature (75 F.), while the firstsolution did not become clear until 95 F.

One gallon of each solution was diluted with 5 gallons of Stoddardsolvent. Garments and swatches, which had been drycleaned, were immersedin these solutions, centrifuged and dried at 140 P. All the garments hada Spray Rating of 100. The swatches were tested for stiifness on aDrape-Flex Stiffness Tester. The swatches treated with the secondsolution were less stiff than those treated with the first solution(12.8 in. vs. 13.9 in. bending length).

The foregoing data show the improved results which are obtained byincorporating the polymerized beta-pinene in the composition.

Example 4 In this operation, water-repellent solutions were preparedhaving the same general composition as that (incorponating thepolymerized beta-pinene) described above in Example 3, except that herethe tetraisopropyl titanate content was held at 6% in one series, at 9%in another, and at 12% in still a third. In each series the content ofglycol was varied, as indicated in Table I below. Those compositionsmarked with an asterisk were unstable due to the use of insufficientglycol. It will be seen that approximately 0.3 mole of glycol per moleof titanate is required to stabilize the latter. Also, poorer SprayRatings are obtained as the content of glycol approaches or exceeds 0.5mole per mole of titanate.

1 Mole G/Mole T moles of glycol per mole of titanate. Indicate solutionclouded on standing for 24 hours.

ExampleS The water-repellent solution of Example 3 (containingpolymerized beta-pinene and 0.434 mole glycol per mole of titanate) wasused to successively treat garments totaling lbs. in weight. The SprayRating of each garment was 100. On the other hand, when this operationwas repeated using a similar solution, but with 0.474 mole glycol permole of titanate, the Spray Rating had fallen to 80 by the time the 20thgarment had been processed. This indicates the desirability of using theleast amount of glycol possible commensurate with obtaining a stablesolution.

Example 6 In this operation water-repellent solutions were preparedusing the following composition:

Parts Polymerized octadecyl vinyl ether l8 Polymerized beta-pinene 3 and2-ethyl-1,3-hexandiol in varying proportions, as in- TABLE II MolesGlycol per Mole of Glycol Content, Parts by Wt.

Titanate Spray Rating It should be observed that a strong synergisticeffect is obtained as a glycol-stabilized titanate ester is employed inconnection with a vinyl ether polymer. This is evidenced by thefollowing tests:

A solution containing 2.0% tetraisopropyl titanate and 0.3% hexyleneglycol in Stoddard solvent was prepared. A swatch of cotton poplin whichhad been drycleaned using a commercial drycleaning detergent and dried,was immersed in the solution, passed through squeeze rolls and dried for30 minutes at 15 C. The fabric was then pressed on a commercial steampress. This fabric had a Spray Rating of 0. A second solution wasprepared containing 4% of a polymerized octadecyl vinyl ether inStoddard solvent, and drycleaned cotton fabric treated as before. Thisfabric had a Spray Rating of 0. A third solution was prepared containing2% tetraisopropyl titanate, 0.3% hexylene glycol and 4% of thepolymerized octadecyl vinyl ether. The drycleaned fabric treated withthis solution had a Spray Rating of 100.

We claim as our invention:

1. A composition for rendering fabric water-repellent, said compositioncomprising a solution in an organic solvent of from 2 to 5 parts of a C-C alkyl vinyl ether polymer, from 1 to 4 parts of a tetraalkyl titanatewherein the alkyl groups each contain from three to eight carbon atoms,and a C -C glycol of the type having at least one secondary hydroxylgroup, said glycol being present in an amount ranging from 0.1 to 0.5mole per mole of said titanate, which amount is at least sufficient tostabilize the titanate against hydrolysis.

2. The composition of claim 1 wherein the non-solvent portion of saidcomposition comprises from about 2 to 5 parts of polymerized vinyloctadecyl ether and from about 1 to 4 parts of tetraisopropyl titanate,and wherein the glycol employed is hexylene glycol.

3. A composition for rendering fabric water-repellent, said compositionbeing a solution in an organic solvent wherein the non-solventcomponents compri e from about 2 to 5 parts of a C -C alkyl vinyl etherpolymer; from about 1 to 4 parts of a tetraalkyl titanate wherein thealkyl groups each contain from 3 to 9 carbon atoms; an amount effectiveto stabilize said titanate against hydrolysis of a C -C glycol of thetype having at least one secondary hydroxyl group, said amount rangingfrom about 0.1 to 0.5 mole per mole of titanate; from 50 to of whitemineral oil, based on the weight of vinyl ether polymer; and from about10 to 25%, based on the weight of said vinyl ether polymer, of apolymerized beta-pinene.

4. The composition of claim 3 wherein the vinyl ether polymer ispolymerized octadecyl vinyl ether, the titanate is tetraisopropyltitanate, and the glycol is hexylene glycol.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Green 117143 XR Mailander 260-33.8 5 Haslam 117-121Staubly et a1 117-121 Speel et a1.: Textile Chemicals and Auxiliaries,2nd ed., Reinhold Publishing Corp., New York (1957), pp. 252, 253, and299.

MORRIS LIEBMAN, Primary Examiner. LEON J. BERCOVITZ, Examiner.

1. A COMPOSITION FOR RENDERING FABRIC WATER-REPELLENT, SAID COMPOSITIONCOMPRISING A SOLUTION IN AN ORGANIC SOLVENT OF FROM 2 TO 5 PARTS OF AC12-C22 ALKYL VINYL ETHER POLYMER, FROM 1 TO 4 PARTS OF A TETRAALKYLTITANATE WHEREIN THE ALKYL GROUPS EACH CONTAIN FROM THREE TO EIGHTCARBON ATOMS, AND A C6-C9 GLYCOL OF THE TYPE HAVING AT LEAST ONESECONDARY HYDROXYL GROUP, SAID GLYCOL BEING PRESENT IN AN AMOUNT RANGINGFROM 0.1 TO 0.5 MOLE PER MOLE OF SAID TITANATE, WHICH AMOUNT IS AT LEASTSUFFICIENT TO STABLIZE THE TITANATE AGAINST HYDROLYSIS.